Factual Information
On 18 March 2014 at 1430 local time, a Eurocopter AS350 B3 (registration LN-OFC, serial number 2009) operated by Helitrans AS experienced a serious incident while landing at Selnesåsen in Lyngen, Troms, Norway. The helicopter was on a non-scheduled commercial flight transporting four workers and equipment to a telecommunications mast. Weather was reported as CAVOK with wind from the south at 3–10 knots. The flight was conducted in daylight under visual meteorological conditions (VMC) in uncontrolled Class G airspace. The aircraft was powered by a Turbomeca Arriel 2B1 engine.
Sequence of Events
The helicopter, based at Helitrans' facility in Narvik, had been performing multiple tasks in the area east of Tromsø that day. Earlier, it conducted a survey flight and transported materials to two other telecom masts. The final task involved lifting a 200 kg winch (hiv) using a 15-meter long line to the mast at approximately 350 meters elevation. That lift was completed without incident. The helicopter then returned to the loading area to pick up four passengers. Without stopping the engine, the pilot flew towards a designated landing point east of the mast and south of a power line supplying the mast. The pilot estimated the power line height at about 4 meters. The loadmaster, seated in the left seat, was tasked with opening the door to gauge distance to the ground and clear the tail rotor. As the helicopter approached the landing point and neared the ground, the main rotor stirred up snow, creating a white-out condition that caused the pilot to lose visual references. The helicopter drifted forward unintentionally and passed under the power line, which struck the anti-collision light mounted on the vertical fin, tearing it off. The pilot felt a jolt. Visibility improved as the helicopter passed the line, and the pilot executed a safe landing to drop off passengers and inspect the damage. The pilot contacted the company's flight operations manager, who, after consulting with technical staff, decided the helicopter could be flown to Tromsø Airport if the pilot was comfortable.
Investigation Findings
According to the Norwegian Meteorological Institute, dry snow had fallen daily from 13 March, with sub-zero temperatures at the mast altitude, creating conditions conducive to snow being whipped up. The helicopter's operations manual (OM-E) addressed white-out risks, stating that landings should not be performed when white-out is anticipated and providing procedures to mitigate it. The pilot had 920 total flight hours on helicopters, with 360 on the AS350, but the company's minimum requirement for mountain area operations was 1,000 hours. The investigation noted that the landing point was chosen south of the power line, and the approach from the south placed the line ahead of the helicopter, becoming an obstacle for a rejected landing. The report observed that if the line had contacted the main or tail rotor, the outcome could have been more severe. The investigation also considered the company's landing site selection procedures (OM-A Chapter 8.3.1) and white-out guidance (OM-E Chapter 2.1.6.3) to be insufficiently detailed for planning approaches in snow-prone areas. The company had since begun revising its documentation for such operations.
Damage
The anti-collision light on the vertical fin was torn off. No other damage to the aircraft was reported. No injuries to the six occupants (pilot, loadmaster, four passengers) occurred.